Many of us who’ve been in long term marriages have experienced this, the only difference is that some of us like me, are divorced.
It’s heartening to know you both are still hanging in there. You are not bad at communicating, you both have lost the ability to communicate with each other.
I don’t know about couples therapy being helpful, but each of you can benefit from individual therapy. A lot of soul searching and honesty.
Physical touch and intimacy is important, but more important is the will to contribute towards one’s and the other’s spiritual growth in the relationship. Feeling lifeless in a marriage is no way to live.